Device for loading an embolic protection filter into a catheter

ABSTRACT

A device for loading an embolic protection filter into a catheter including a loading member for collapsing an embolic protection filter, wherein an outlet of the loading member is configured to be aligned with an inlet of a catheter extending along at least part of an exterior surface of the catheter for loading of the collapsed embolic protection filter into the catheter. The loading member may have a passageway extending therethrough, through which an embolic protection filter may be passed to collapse the embolic protection filter. The outlet of the loading member may include an outlet of the passageway that is at least partially funnel-shaped. The loading member may include a tubular part extendable along part of an exterior surface of a catheter, the outlet of the loading member being provided at an end of the tubular part.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/408,732, filed Apr. 18, 2006, which claims the benefit of U.S. Patentapplication Ser. No. 60/672,442, filed Apr. 18, 2005, both of which arehereby incorporated by reference in their entirety.

INTRODUCTION

This invention relates to a device and a method for loading an embolicprotection filter into a catheter.

STATEMENTS OF INVENTION

According to the invention there is provided a device for loading anembolic protection filter into a catheter, the device comprising:

an engagement member for engaging an embolic protection filter to loadthe embolic protection filter into a catheter; and

a controller to control the loading force exerted on the embolicprotection filter during loading into the catheter.

By controlling the loading force exerted, the controller prevents damagebeing inadvertently caused during loading of the filter.

The controller prevents the user inadvertently applying an excessiveloading force to the embolic protection filter, for example when thefilter is fully loaded into the catheter. If this were to occur, thisextra loading force could lead to damage to the filter and/or to thecatheter, and/or could lead to the loaded filter being incorrectlypositioned in the catheter.

In one embodiment of the invention the controller is provided by a firstpart of the device being movable relative to a second part of thedevice. The first part of the device may be movable relative to thesecond part of the device between an extended configuration and aretracted configuration. The device may be biased towards the extendedconfiguration. The device may comprise a biasing member to bias thedevice towards the extended configuration. The biasing member maycomprise a coiled spring.

In another embodiment the first part of the device comprises a handlepart. The second part of the device may comprise the engagement member.

In a further embodiment the engagement member comprises a pusher forengaging an embolic protection filter to push the embolic protectionfilter into a catheter. The engagement member may comprise a puller forengaging an embolic protection filter to pull the embolic protectionfilter into a catheter.

The engagement member may be provided on an elongate stem. Theengagement member may be integral with the stem. The engagement membermay comprise a step in the stem from a small diameter portion to a largediameter portion. The stem may comprise a wire.

In another aspect the invention provides a method of loading an embolicprotection filter into a catheter, the method comprising the steps of:

engaging the embolic protection filter; and

loading the embolic protection filter into the catheter, the loadingforce exerted on the embolic protection filter being automaticallycontrolled during loading.

In one embodiment loading of the embolic protection filter into thecatheter causes a first part of a controller to move relative to asecond part of the controller. The embolic protection filter may beloaded into the catheter by pushing the embolic protection filter intothe catheter. The embolic protection filter may be loaded into thecatheter by pulling the embolic protection filter into the catheter.

In another aspect of the invention, there is provided a device forloading an embolic protection filter into a catheter, the devicecomprising:

a loading member for collapsing an embolic protection filter;

an outlet of the loading member, being configured to be aligned with aninlet of a catheter extending along at least part of an exterior surfaceof the catheter for loading of the collapsed embolic protection filterinto the catheter.

Because the outlet of the loading member extends along the exteriorsurface of the catheter, this ensures that, when the embolic protectionfilter is loaded, the loaded catheter can be quickly and simplydisassociated from the loading member, and inserted into the vasculatureof a patient. In particular the loaded catheter may be quickly withdrawnfrom the catheter without the risk that the embolic protection filterwill remain in the loading member. In addition during loading of theembolic protection filter, it is not necessary to move the catheterrelative to the loading member to effect a complete loading of thefilter into the catheter.

Furthermore the wall space and profile of the catheter assembly may beminimised by arranging the outlet of the loading member along theexterior of the catheter.

In one embodiment the loading member has a passageway extendingtherethrough, through which an embolic protection filter may be passedto collapse the embolic protection filter. The outlet of the loadingmember may comprise an outlet of the passageway. An inlet of thepassageway may have a larger cross-sectional area than the outlet of thepassageway. The passageway may be at least partially funnel-shaped.

In another embodiment the loading member comprises a tubular partextendable along part of an exterior surface of a catheter, the outletof the loading member being provided at an end of the tubular part. Thepassageway may extend through the tubular part in a substantiallycylindrical shape.

In another embodiment the embolic protection system includes loadingmeans for loading the filter into the delivery catheter. Ideally theloading means comprises a funnel having a narrowed portion disposed atthe distal end of the delivery catheter and an enlarged portion forreceiving a proximal portion of the filter in the expandedconfiguration, the filter being progressively collapsed as it is movedthrough the funnel for loading into the delivery catheter.

The invention also provides in another aspect a method of loading anembolic protection filter into a catheter, the method comprising thesteps of:

arranging a loading member relative to the catheter with an outlet ofthe loading member aligned with an inlet of the catheter and with theoutlet of the loading member extending along at least part of anexterior surface of the catheter;

collapsing the embolic protection filter; and

loading the collapsed embolic protection filter into the catheter.

In another embodiment the embolic protection filter is collapsed bypassing the embolic protection filter through the loading member. Themethod may comprise the step of disassociating the catheter from theloading member after loading of the collapsed embolic protection filterinto the catheter. The catheter may be disassociated from the loadingmember by withdrawing the catheter from within the outlet of the loadingmember. The catheter may be withdrawn by gripping the catheter andmoving the catheter while the loading member remains stationary.

In another aspect of the invention there is provided an assembly forloading an embolic protection filter into a catheter, the assemblycomprising one or more devices of the invention.

In a further aspect the invention provides a device for loading anembolic protection filter into a catheter, the device comprising:

an engagement member for engaging an embolic protection filter to movethe embolic protection filter relative to a catheter to load the embolicprotection filter into the catheter;

the loading device being configured to automatically flush the embolicprotection filter and/or the catheter upon movement of the engagementmember relative to the catheter.

By automatically flushing the embolic protection filter and the catheterduring the loading of the filter into the catheter, this provides for afaster and simpler preparation, before the loaded catheter is insertedinto the vasculature of a patient.

In one embodiment the device comprises a bath for immersing an embolicprotection filter in a flushing liquid before loading into a catheter.The bath may be sealable. Because the bath can be sealed, the filter canbe stored and/or transported while immersed in the flushing liquid forpotentially relatively long periods of time. The engagement member maybe movable relative to the bath to move an embolic protection filterrelative to a catheter. The engagement member may be configured to moverelative to the bath while maintaining a seal with a wall of the bath.The engagement member may comprise a plunger.

In another embodiment the device comprises a lock to lock the positionof the engagement member. The device may comprise a stop to resistmovement of the catheter during loading of the embolic protectionfilter. The stop may be configured to facilitate movement of thecatheter after loading.

In a further embodiment the engagement member comprises a pusher forengaging an embolic protection filter to push the embolic protectionfilter into a catheter. The engagement member may comprise a puller forengaging an embolic protection filter to pull the embolic protectionfilter into a catheter. The device may comprise a controller to controlthe loading force exerted on the embolic protection device duringloading into a catheter. The controller may comprise a coiled spring.

The invention provides in a further aspect a method of loading anembolic protection filter into a catheter, the method comprising thesteps of:

engaging the embolic protection filter;

moving the embolic protection filter relative to the catheter to loadthe embolic protection filter into the catheter;

the step of moving the embolic protection filter relative to thecatheter causing an automatic flushing of the embolic protection filterand/or the catheter.

In one embodiment the embolic protection filter is immersed in aflushing liquid before loading. The method may comprise the step ofsealing the embolic protection filter immersed in the flushing liquid.The step of moving the embolic protection filter relative to thecatheter may cause at least some of the flushing liquid to move relativeto the embolic protection filter and/or relative to the catheter. Theembolic protection filter may be pushed into the catheter. The embolicprotection filter may be pulled into the catheter.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the followingdescription of some embodiments thereof, given by way of example only,with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a pack containing an embolic protectionfilter, a catheter assembly, and two devices according to the inventionfor loading the embolic protection filter into the catheter assembly;

FIGS. 2 to 4 are cross-sectional, side views of the first loading deviceof FIG. 1;

FIG. 5 is an enlarged, cross-sectional, side view of a part of the firstloading device of FIGS. 2 to 4;

FIG. 6 is a perspective view of the second loading device of FIG. 1;

FIG. 7 is a side view of the second loading device of FIG. 6;

FIG. 8 is a cross-sectional, side view of the second loading device ofFIG. 6;

FIGS. 9 and 10 are perspective views illustrating release of the firstloading device of FIG. 6;

FIG. 11 is a view along line A-A in FIG. 10;

FIGS. 12 to 15 are side views illustrating loading of the embolicprotection filter of FIG. 1 into the catheter assembly using the firstloading device of FIGS. 2 to 4 and the second loading device of FIG. 6;

FIG. 15A is an enlarged, side view of the embolic protection filterloaded into the catheter assembly;

FIG. 16 is a perspective view of the pack of FIG. 1 after loading of theembolic protection filter of FIG. 1 into the catheter assembly;

FIG. 17 is an enlarged, perspective view of a part of the pack of FIG.16;

FIG. 18 is a perspective view of a pack containing an embolic protectionfilter, a catheter assembly, and a device according to the invention forloading the embolic protection filter into the catheter assembly;

FIG. 19 is an enlarged, perspective view of the embolic protectionfilter and the loading device of FIG. 18;

FIGS. 20 to 23 are perspective views illustrating loading of the embolicprotection filter of FIG. 19 into the catheter assembly of FIG. 18;

FIGS. 23A and 23C are partially cut-away, perspective views of anotherdevice according to the invention for loading an embolic protectionfilter into a catheter assembly;

FIG. 24 is a perspective view of a pack containing an embolic protectionfilter, a catheter assembly, and a device according to the invention forloading the embolic protection filter into the catheter assembly;

FIGS. 25 to 27 are enlarged, perspective views of a part of the pack ofFIG. 24;

FIGS. 27A to 27D are perspective views illustrating loading of theembolic protection filter into the catheter assembly;

FIGS. 28 and 29 are perspective views of a further pack containing anembolic protection filter, a catheter assembly, and a device accordingto the invention for loading the embolic protection filter into thecatheter assembly;

FIGS. 30 to 37 are enlarged, perspective views of parts of the pack ofFIGS. 28 and 29;

FIGS. 38 and 39 are perspective views of other packs;

FIGS. 40 to 43 are perspective views of a further device according tothe invention for loading an embolic protection filter into a catheterassembly;

FIG. 44 is a perspective view of a pack containing an embolic protectionfilter, a catheter assembly, and two devices according to the inventionfor loading the embolic protection filter into the catheter assembly;

FIG. 45 is a perspective view of the first loading device of FIG. 44;

FIG. 46 is a cut-away, perspective view of the loading device of FIG.45;

FIG. 47. is a view similar to FIG. 46 of another loading deviceaccording to the invention;

FIG. 48 is a perspective view of the second loading device of FIG. 44;

FIG. 49 is a cross-sectional, side view of the loading device of FIG.48; and

FIG. 50 is a perspective view of the loading device of FIG. 48 mountedin the tray of FIG. 44.

DETAILED DESCRIPTION

Referring to the drawings, and initially to FIGS. 1 to 17 thereof, thereis illustrated a transvascular embolic protection system for safelycapturing and retaining embolic material released during aninterventional procedure while maintaining blood flow.

The embolic protection system comprises an embolic protection device 1and a delivery catheter 2 for delivery of the embolic protection device1 to a desired location in the vascular system. The device 1 iscollapsible from an expanded deployed configuration to a retracteddelivery configuration. The delivery catheter 2 has a pod 13 at thedistal end to define a reception space for the embolic protection device1 in the collapsed delivery configuration.

In use, the embolic protection device 1 is loaded into the pod 13 of thedelivery catheter 2 which is delivered over a pre-positioned guidewire.At a desired location, the embolic protection device 1 is deployed fromwithin the pod 13. The delivery catheter 2 is then withdrawn leaving abare guidewire over which various devices such as a dilation balloonand/or a stent can be advanced to the treatment site. Embolic materialdislodged during the treatment procedure(s) is collected in the embolicprotection device 1. After treatment, the device 1 may be retrieved intoa retrieval catheter. The guidewire may be left in place for furthercatheter advancements or may be withdrawn with or subsequent to thewithdrawal of the retrieval catheter.

Referring in particular to FIG. 1, a pack 4 is provided to safely storeand prepare the embolic protection system for use. The pack 4 comprisesa vacuum-formed tray 5, typically of PETG. The tray 5 has a channel 6extending in a looped configuration around the tray 5 for receiving thedelivery catheter 2. The delivery catheter 2 has a distal end 12. Thepod 13 is provided at the distal end 12 of the inner catheter 2. Aloading device 7 according to the invention, which in this case is inthe form of a funnel piece, is mounted in the tray 5 adjacent to andextending along an exterior surface of the pod 13. The embolicprotection device 1 is mounted in its expanded configuration in a well90 in the tray 5. A pushing device 8 according to the invention forloading the collapsible embolic protection device 1 into the deliverycatheter 2 is mounted in the tray 5 adjacent to the embolic protectiondevice 1. The pushing device 8 is used to push the embolic protectiondevice 1 through the loading device 7 and into the pod 13 of thedelivery catheter 2 in the collapsed configuration. The deliverycatheter 2 is now ready for advancement over a guidewire.

Referring now to FIGS. 2 to 5, the pushing device 8 according to theinvention for loading the collapsible filter element into the pod 13 ofthe delivery catheter 2 is illustrated. The pushing device 8 comprises ahandle 70 for gripping the pushing device 8 and an elongate stem in thiscase provided by a wire 71, extending from the handle 70 for threadingthrough the filter element. The wire 71 defines an engagement member, inthis case provided in the form of a distal stop 72, for releasablyengaging with the distal end of a sleeve of a filter element to push thefilter element into the pod 13 of the delivery catheter 2.

As illustrated in FIG. 5 the distal stop 72 is provided by an end 74 ofan outer hypotube 73 which extends from the handle 70 partially alongthe wire 71. The free end 74 of the hypotube 73 forms a step from thesmall diameter wire 71 proximal of the step to the larger diameterhypotube 73 distal of the step. The small diameter is preferablyapproximately 0.014″ (0.3556 mm), and the large diameter is preferablyapproximately 0.018″ (0.4572 mm). The hypotube 73 may be attached to thewire 71 by any suitable means, such as an adhesive means, or amechanical keying means, or by brazing, or soldering, or welding, or byany other suitable means.

As illustrated in FIGS. 2 to 4, the handle 70 is movable relative to thewire 71 between an extended configuration (FIG. 2) and a retractedconfiguration (FIG. 4). A coiled spring 200 is housed within the handle70 bearing against the wire 71 to bias the pushing device 8 towards theextended configuration.

Upon engagement of the distal stop 72 with the filter element andpushing of the filter element, the engagement pushing force applied bythe wire 71 on the filter element is balanced by an equal and oppositeforce exerted by the filter element on the wire 71. As the pushing forceis increased to load the filter element, the opposite force graduallyovercomes the biasing force of the spring 200, causing the spring 200 tocompress and thereby moving the pushing device 8 from the extendedconfiguration (FIG. 2) to the retracted configuration (FIG. 4).

The stiffness of the spring 200 is selected to enable a safe loadingforce to be applied to load the filter element into the pod 13 of thedelivery catheter 2. However if it is attempted to apply an excessiveloading force the spring 200 compresses, thus preventing excessive loadsbeing transferred to the system. Thus the movement of the handle 70relative to the wire 71 acts as a controller to control the loadingforce exerted on the filter element during loading into the deliverycatheter 2. In this way, the device 8 allows a safe loading force to beapplied to the system, and prevents damage being inadvertently causeddue to excessive loading forces.

The wire 71 may have a low friction coating, for example ofpolytetrafluoroethylene, for ease of threading of the wire 71 throughthe filter element. The handle 70 facilitates ease of gripping and ofuse of the pushing device 8.

It will be appreciated that the distal stop 72 may be provided integralwith the wire 71, for example by machining a step in the wire 71.

It will further be appreciated that the large diameter portion distal ofthe step may be only a locally defined feature on the wire 71 that doesnot extend distally to the handle 70.

It will be appreciated that the filter element may alternatively bepulled into the pod 13 of the delivery catheter 2 using a suitablepulling device.

The loading device 7 for loading the filter element into the pod 13 ofthe delivery catheter 2 is illustrated in detail in FIGS. 6 to 8. Theloading device 7 defines a funnel having an inlet end 80 and an outletend 81, the inlet end 80 defining a larger cross-sectional area than theoutlet end 81, and the outlet end 81 being configured for co-operativealignment with the inlet of the delivery catheter 2, and for extendingalong the exterior surface of the delivery catheter 2.

The loading device 7 has means for collapsing the filter element byradially compressing the filter element from the extended outwardlyprojecting position to the collapsed position. In this case, the loadingdevice 7 comprises a main support 82 having a funnel-shaped bore formedfrom a frusto-conical filter element receiving portion terminating and acylindrical portion formed by a thin walled loading tube 83 projectingfrom the main support 82 for positioning extending along the exteriorsurface of the delivery catheter 2. A passageway is provided through themain support 82 and through the loading tube 83. By passing the filterelement through the passageway, the filter element is collapsed.

The cone angle of the bore is chosen from an angle in the range ofbetween 15° and 65°, preferably between 35° and 45°.

The loading tube 83 is preferably formed from polyethyleneterephthalate(PET), and is mounted on a metal spigot, typically a grit blastedhypotube, by a combination of a polyolefin shrink tube bond and anadhesive bond. The metal spigot is adhesively fixed to the main support82 which is formed from “Perspex” or a similar material. The loadingtube 83 may be coated with a lubricant.

Referring to FIGS. 1 and 9 to 11, the tray 5 will now be described infurther detail. The tray 5 includes integral projections 9 that extendinto various recesses. The projections 9 releasably support the loadingdevice 7 in co-operative alignment with the delivery catheter 2 beforeloading and during the loading procedure. In particular, the loadingdevice 7 is supported with the loading tube 83 extending proximallyalong an exterior surface of the delivery catheter 2 before loading andduring the loading procedure. In addition, the projections 9 on thechannel wall are configured to releasably support the pushing device 8in a position in which the distal stop 72 does not engage the filterelement before the loading procedure commences.

A liquid retaining bath 90 is provided by a recess in the tray 5, thebath 90 having a depth sufficient to accommodate in a totally submergedstate the reception space of the delivery catheter 2 and the filterelement for submerged loading of the filter element through the loadingdevice 7 and into the pod 13 of the delivery catheter 2. As illustratedin FIG. 1, the channel 6 communicates with the bath 90.

The components of the embolic protection system are placed in the pack 4in the following manner. The loading device 7 is snapped into place inthe channel 6, with the projections 9 releasably supporting the loadingdevice 7 in the position illustrated in FIG. 1.

The catheter 2 is looped through the channel 6 and held in place so thatthe loading tube 83 of the loading device 7 extends proximally along theexterior surface of the delivery catheter 2, and the outlet end 81 ofthe loading tube 83 is aligned with the inlet of the delivery catheter2.

The wire 71 of the pushing device 8 is then threaded through the filterelement, a proximal end of the wire 71 is inserted through the loadingdevice 7 and extended partially through the catheter 2. The handle 70 issnapped into place in the channel 6 by the projections 9. In thisconfiguration the filter element is slidable over the wire 71 but isnormally positioned within the bath 90, as illustrated in FIG. 1. Theprojections 9 retain the pushing device 8 in a position in which thedistal stop 72 is spaced distally of the bath 90, and so the distal stop72 does not engage the filter element in this storage configuration, asillustrated in FIG. 1.

In this storage configuration the filter element is in the expandedconfiguration. The assembled pack 4 of the invention may be safelystored for long periods in a packaged configuration without risk offilter element material deformation, such as material creep. The pack 4is placed in a porch and sealed.

When the assembled pack 4 is required for use, the seal is broken, andthe pack 4 is removed.

The filter element is now ready for loading into the pod 13 of thedelivery catheter 2. The pushing device 8 is rotated through 90° in a“bolt-action” to release the handle 70 from the snap-fit retainingprojections 9 in the tray 5, as illustrated in FIGS. 9 and 10. In thisconfiguration the pushing device 8 is still retained in the tray 5 (FIG.11). The pushing device 8 is now free to slide proximally in the channel6, until the distal stop 72 engages with the distal end of the sleeve ofthe filter element (FIG. 12). Continued pushing of the pushing device 8will push the filter element 40 proximally towards the loading device 7(FIG. 13), through the loading device 7 (FIG. 14), thereby collapsingthe filter element from the extended outwardly projecting position tothe collapsed position, and loading the filter element into the pod 13of the delivery catheter 2.

As the filter element is pushed through the loading device 7, thepushing force required to load the filter element gradually increases.This increase in force causes an initial compression of the spring 200,as illustrated in FIGS. 13 and 14. This initial compression is caused asa result of the loading of the filter into the pod 13.

The spring 200 then compresses further, as illustrated in FIGS. 14 and15. This further compression accommodates any dimensional tolerances inthe system. FIG. 15A illustrates the filter loaded into the pod 13, withthe pod 13 being located within the loading tube 83.

When the device 8 is in this retracted configuration with the spring 200fully compressed, the handle 70 is snapped into position in a secondrecess by means of retaining projections 9 (FIG. 16). This second recessis spaced to ensure that the handle 70 may only be snapped into positionwhen the spring 200 is fully compressed. This arrangement thereforeguarantees that the correct loading force is applied and the filter isfully loaded.

The loading device 7 has thus far remained in co-operative alignmentwith the delivery catheter 2. The loaded catheter assembly may begripped and pulled proximally in the channel 6 away from the stationaryloading device 7 to withdraw the pod 13 of the delivery catheter 2 fromwithin the outlet 81 of the loading tube 83. In this manner, thedelivery catheter 2, and the collapsed filter element are moved togetherproximally away from the loading device 7, and thereby the loadedcatheter assembly is disassociated from the loading device 7.

The loaded catheter assembly is then removed from the channel 6 leavingthe loading device 7 and the pushing device 8 behind in the channel 6.The loaded delivery catheter 2 is now ready for insertion into avascular system of a patient.

The components of the pack 4 are retained in the correct loadingalignments by the tray 5. The pushing device 8 is completely separatedfrom the loaded catheter assembly after completion of the loadingprocedure.

In addition, the loaded filter element is not attached or associated inany way with the pushing device 8. Thus, the user is free to choose anysuitable guidewire, as desired, for subsequent delivery of the filterelement through a vascular system of a patient.

Shortest catheter length: In one embodiment, when the filter is loaded,the spring has compressed by 20 mm, a 5 N load is placed on the filter.

Longest catheter length: In one embodiment, when the filter is loaded,the spring has compressed by 30 mm, a 6 N load is placed on the filter.

In FIGS. 18 to 23 there is illustrated another transvascular embolicprotection system, which is similar to the system of FIGS. 1 to 17, andsimilar elements in FIGS. 18 to 23 are assigned the same referencenumerals.

In this case the embolic protection device 1 is positioned in the bath90, and the bath 90 is filled with a flushing liquid, such as a salinesolution, to immerse the filter element. The bath 90 is then sealed witha transparent film 201. The assembled pack 4 may be stored with thesaline solution sealed within the bath 90, until required for use.

Alternatively the bath 90 may be open and be filled with saline solutiononly when required for use.

The engagement member is provided in this case by a syringe plunger 202.The plunger 202 is movable through the bath 90 to engage the filterelement, while maintaining a seal between the plunger 202 and the wallsof the bath 90.

When the assembled pack 4 is required for use, the plunger 202 isdepressed to push the filter element through the loading device 7 tocollapse the filter element, and to load the filter element into the pod13 of the delivery catheter 2.

Because the saline solution is sealed within the bath 90, the step ofdepressing the plunger 202 also causes the flushing liquid in the bath90 to move around the filter element and through the catheter assembly,and thus automatically flush the filter element and the catheterassembly.

As an alternative to the moveable plunger 202 of FIGS. 18 to 23, apre-loaded spring 300 may be used to load the filter 1 into the pod 13of the delivery catheter 2, as illustrated in FIGS. 23A and 23C. Areleasable clasp 301 may be used to hold the spring 300 in a compressedstate until it is desired to load the filter 1, at which time the clasp301 may be released.

As illustrated in FIGS. 24 to 27, a coiled spring 210 may be providedextending around the plunger 202. The plunger 202 engages the filterelement 1 in the bath 90, and the spring 210 engages a proximal end ofthe bath 90. In this manner the spring force prevents excessive loadingforces being applied to the system to minimise the possibility of damagebeing caused during loading.

The process of loading of the filter 1 into the pod 13 of the catheter 2is illustrated in FIGS. 27A to 27D. As the plunger 202 is advancedthrough the bath 90, the spring 210 is compressed, thus controlling thepushing force exerted on the filter 1.

As an alternative to using a plunger, a handle mechanism 220 may be usedto load the filter 1 into the pod 13, as illustrated in FIGS. 28 to 37.The handle mechanism 220 is movable relative to the pack 5 to move thefilter 1 relative to the pod 13 for loading into the pod 13.

A lock mechanism 221 is provided to lock the handle 220 in positionuntil it is desired to load the filter 1. The lock 221 may then beopened by rotating the lock mechanism.

A block 222 of elastomeric material, such as rubber is providedproximally of the pod 13. The block 222 engages against the proximal endof the pod 13 to prevent movement of the catheter 2 during loading ofthe filter 1. When the filter 1 is fully loaded into the pod 13, furtherpushing force applied at the handle mechanism 220 overcomes theelastomeric force of the block 222 to push the loaded pod 13 proximallythrough the block 222.

The block 222 thus acts as a means of controlling the force applied tothe system during loading.

A spring 230 may be provided between the handle mechanism 220 and thefilter element 1, as illustrated in FIGS. 38 and 39. The spring forceprevents excessive loading force being applied to the system.

FIGS. 40 to 43 illustrate passage of the plunger 202 through the bath 90to load the filter 1 into the pod 13 with a combined flushing of thefilter 1 and/or the catheter 2.

Referring to FIGS. 44 to 50 there is illustrated another transvascularembolic protection system, which is similar to the system of FIGS. 1 to17, and similar elements if FIGS. 44 to 50 are assigned the samereference numerals.

An end cap 500 is releasably attached to the pushing device 8 in asnap-fit manner to aid assembly (FIG. 46). It will be appreciated thatthe end cap 500 may be attached to the pushing device 8 in a variety ofpossible means, for example by means of a screw-thread or by means of anadhesive.

A ridge 501 may be provided to assist in keeping the spring 502 in thedesired position relative to the handle 70 (FIG. 47).

In this case the loading device 7 is provided in the form of a one-pieceloading funnel (FIG. 49). As illustrated in FIG. 50, a snap-fitprojection 503 on the channel 6 holds the proximal end of the loadingdevice 7 in position. A corner edge 504 at the end of the channel 6provides an abutment during loading of the filter 1.

The invention is not limited to the embodiments hereinbefore described,with reference to the accompanying drawings, which may be varied inconstruction and detail.

1-7. (canceled)
 8. A method of loading an embolic protection filter intoa catheter, the method comprising the steps of: engaging the embolicprotection filter; and loading the embolic protection filter into thecatheter, the loading force exerted on the embolic protection filterbeing automatically controlled during loading.
 9. A method as claimed inclaim 8, wherein loading of the embolic protection filter into thecatheter causes a first part of a controller to move relative to asecond part of the controller.
 10. A method as claimed in claim 8,wherein the embolic protection filter is loaded into the catheter bypushing the embolic protection filter into the catheter.
 11. A method asclaimed in claim 8, wherein the embolic protection filter is loaded intothe catheter by pulling the embolic protection filter into the catheter.12. A method of loading an embolic protection filter into a catheter,the method comprising the steps of: arranging a loading member relativeto the catheter with an outlet of the loading member aligned with aninlet of the catheter and with the outlet of the loading memberextending along at least part of an exterior surface of the catheter;collapsing the embolic protection filter; and loading the collapsedembolic protection filter into the catheter.
 13. A method as claimed inclaim 12, wherein the embolic protection filter is collapsed by passingthe embolic protection filter through the loading member.
 14. A methodas claimed in claim 12, wherein the method comprises the step ofdisassociating the catheter from the loading member after loading of thecollapsed embolic protection filter into the catheter.
 15. A method asclaimed in claim 14, wherein the catheter is disassociated from theloading member by withdrawing the catheter from within the outlet of theloading member.
 16. A method as claimed in claim 15, wherein thecatheter is withdrawn by gripping the catheter and moving the catheterwhile the loading member remains stationary.
 17. A device for loading anembolic protection filter into a catheter, the device comprising: anengagement member for engaging an embolic protection filter to move theembolic protection filter relative to a catheter to load the embolicprotection filter into the catheter; the loading device being configuredto automatically flush the embolic protection filter and/or the catheterupon movement of the engagement member relative to the catheter.
 18. Adevice as claimed in claim 17, wherein the device comprises a bath forimmersing an embolic protection filter in a flushing liquid beforeloading into a catheter.
 19. A device as claimed in claim 18, whereinthe bath is sealable.
 20. A device as claimed in claim 18, wherein theengagement member is movable relative to the bath to move an embolicprotection filter relative to a catheter.
 21. A device as claimed inclaim 20, wherein the engagement member is configured to move relativeto the bath while maintaining a seal with a wall of the bath.
 22. Adevice as claimed in claim 21, wherein the engagement member comprises aplunger.
 23. A device as claimed in claim 17, wherein the devicecomprises a lock to lock the position of the engagement member.
 24. Adevice as claimed in claim 17, wherein the device comprises a stop toresist movement of the catheter during loading of the embolic protectionfilter.
 25. A device as claimed in claim 24, wherein the stop isconfigured to facilitate movement of the catheter after loading.
 26. Adevice as claimed in claim 17, wherein the engagement member comprises apusher for engaging an embolic protection filter to push the embolicprotection filter into a catheter.
 27. A device as claimed in claim 17,wherein the engagement member comprises a puller for engaging an embolicprotection filter to pull the embolic protection filter into a catheter.28. A device as claimed in claim 17, wherein the device comprises acontroller to control the loading force exerted on the embolicprotection device during loading into a catheter.
 29. A device asclaimed in claim 28, wherein the controller comprises a coiled spring.30. A method of loading an embolic protection filter into a catheter,the method comprising the steps of: engaging the embolic protectionfilter; moving the embolic protection filter relative to the catheter toload the embolic protection filter into the catheter; the step of movingthe embolic protection filter relative to the catheter causing anautomatic flushing of the embolic protection filter and/or the catheter.31. A method as claimed in claim 30, wherein the embolic protectionfilter is immersed in a flushing liquid before loading.
 32. A method asclaimed in claim 31, wherein the method comprises the step of sealingthe embolic protection filter immersed in the flushing liquid.
 33. Amethod as claimed in claim 31, wherein the step of moving the embolicprotection filter relative to the catheter causes at least some of theflushing liquid to move relative to the embolic protection filter and/orrelative to the catheter.
 34. A method as claimed in claim 30, whereinthe embolic protection filter is pushed into the catheter.
 35. A methodas claimed in claim 30, wherein the embolic protection filter is pulledinto the catheter.